I am going with a 3 inch lift on my 95. I want to put 10 1/2 x 31's under it. I'm thinking of a 15 x 8 wheel. How much backspace do i need on that rim to not rub? What about bump stop? Never done any bump stop work.

 

I think 3.75 backspacing is the most recomended (https://www.cherokeeforum.com/f59/xj...up-thread-260/). Buy extended bumpstops (daystar are the most common) and install them when you do your front lift springs. Otherwise you will be removing your springs to put them in later. Rears are bolt on and can be done whenever. Also there are 2 different diameters of front bumpstops, 1.5" and 2", and older XJs (pre93?) had screw in stops vs the press in kind... but yes you should extend your stops if you want to keep your fender flares.

 

I run 4" backspace and it's perfect. For the tires to stick even more, 3.75" is the way to go, although I heard 4" bs make the wheel right in the center with no offset, while 3.75 do have offset, which makes your ball joints wear out faster.

 

3.75 is the most optimal.

 

Local4x4 store was telling me 15x10 rims with 4.5 bs. A setup with 3" lift, 15x8 rims with 3.75 bs, 31x10.5 tires would go well. What about bump stop sizes? Never worked with them yet.

 

If you plan on disco front and rear. 3" bump should do.

I glued two hockey pucks on the lower spring plate in the front. Works better in my opinion because if you extend the front bumpstop bumpers much you will hit the spring.

Hockey pucks are cheap and shoo goo holds them great!

 

Also just wanted to say that the best way is to figure out how much bump for your application in particular. Since no two jeeps are identical its best to take the time and find out exactly what YOU need.

I may say 3" should do it. But maybe it will rub unless you have 3.5?

You get the idea.